The present invention relates to a wall plug for fastening articles to panels, hollow walls and similar structures, and also solid building materials. Such a wall plug includes a lower end part having a longitudinal bore with an internal thread or internal ribs, and two limbs leading off the lower end part which are held together by means of a top part similarly having a longitudinal bore and provided with a flange and a means for preventing rotation of the plug.
A wide variety of wall plugs of the type mentioned above are known in the art from a number of my numerous prior patents. These plugs being intended for use in both hollow walls and in solid building materials. Ordinarily such wall plugs are provided with more than two limbs. Due to the low rigidity of these limbs against torsion, when a screw is screwed into the longitudinal bore of the lower end part, a twist is achieved which leads to the formation of an enlargement caused by the limbs becoming superimposed upon one another. To achieve a uniform formation of the enlargement it is generally necessary for the wall plug to be made of a very soft plastic material. Use of such a material has the following consequences, firstly, overturning the screw in the longitudinal bore of the lower end part occurs easily resulting in an insignificant tightening moment for fastening an article and, secondly high pull out values cannot be obtained when using the wall plug in solid building materials due to the non-rigid plastic material. In addition, long-term fastening values are inadequate for high-quality fastenings due to the undesirable flow properties of the non rigid plastic material.